For preparing images for printing, look at any of Dan Margulis's Photoshop books. Margulis was doing computer photo prepress for print well before Photoshop was on the scene, but was an early convert to Photoshop, and developed many of the techniques for color correction that have been incorporated auto-magic tools in later versions. It's primarily about global manipulation of curves and recombination of channels--nothing about making goofy "Photoshopped" images. His books are the rare computer books that are really inspirational, to make you want to fire up Photoshop and work with some images.
For preparing images for printing, look at any of Dan Margulis's Photoshop books. Margulis was doing computer photo prepress for print well before Photoshop was on the scene, but was an early convert to Photoshop, and developed many of the techniques for color correction that have been incorporated auto-magic tools in later versions. It's primarily about global manipulation of curves and recombination of channels--nothing about making goofy "Photoshopped" images. His books are the rare computer books that are really inspirational, to make you want to fire up Photoshop and work with some images.